Automatic closing system for bifold overhead doors



April 7, 1970 Filed June 10, 1968 47 J. A. ALTON 2 Sheets-Sheet 1 IN I 1 d] 1 1 l t Aw .lw' m l a A A M//, 22

3 T EU |;l| I I! E {3 W- 44- in! w Ill 72 o f;

F Z 75 6 1ll 5 jgfzo lg 4 g INVENTOR & m 5 52 a 57)} 1' U 'a James A. Ahon ATTORNEYS.

April 7, 1970 J. A. ALTON 3,504,729

AUTOMATIC CLOSING SYSTEM FOR BIFOLD OVERHEAD DOORS Filed June 10, 1968 2 Sheets-Sheet 2 INVENTOR ATTORNEYS.

United States Patent M 3,504,729 AUTOMATIC CLOSING SYSTEM FOR BIFOLD OVERHEAD DOORS James A. Alton, P.O. Box 26, Peoria, II] 61601 Filed June 10, 1968, Ser. No. 735,781 Int. Cl. Ef /10 US. Cl. 160-188 1 Claim ABSTRACT OF THE DISCLOSURE A double folding overhead door is provided with automatically operated latches to pull the door into vertical position and to hold the door in this position. Each latch includes a slide bar with hook which engages an eyebolt on the door. When the latch is closed the actuated door cannot be opened.

The invention concerns a latching system for a double folding overhead door.

Heretofore it has been found difiicult to close and lock double folding overhead doors guided by side rails in a doorway. It has generally been necessary to push the doors manually into a fully closed position after they are lowered, and then to lock the doors by means of a conventional mechanical lock. The present invention avoids this situation by providing electrically operated automatically actuated latches to pull double folded doors into closed position and to hold them in locked position until released.

The invention is adapted for key, pushbutton or remote radio control. The sequence of operation of the system from a closed and locked position of the door may be as follows. A signal or pulse is applied to release the door latches, the door is lifted and stopped in fully open position. The door is later lowered. Then the latches are actuated to pull the door shut and the door remains closed and locked until the latches are again actuated.

For further comprehension of the invention and of the objects and advantages thereof, reference will be had to the following description and accompanying drawings and to the appended claims in which the various novel features of the invention are more particularly set forth.

In the accompanying drawings, forming a material part of this disclosure;

FIGURE 1 is a rear view of a double fold vertical door in closed position;

FIG. 2 is a plan view of a motor employed to actuate the latching mechanism of the system.

FIG. 3 is an enlarged side view of a closed latch, with part of the door shown in vertical section.

FIG. 4 is a central sectional view of the door taken on line 44 of FIG. 1, with the door shown in unlocked condition and latch shown open.

FIG. 5 is a view similar to FIG. 4 with the door shown open.

FIG. 6 is an exploded perspective view of parts of a latch assembly.

FIG. 7 is a simplified diagram of part of an electric circuit employed to actuate a door latch.

Referring first to FIGS. 1-5, there is shown a double door 10 in which an upper section 12 is pivotally secured to overhead panel 14 of a doorway 16 by means of hinges 18. The lower door section 20 is pivotally secured to the bottom of the upper door section by hinges 22. At sides of the doorway are vertical rails 24 in which are engaged rollers 26 mounted at lower rear corners of the bottom section.

The door is raised and lowered by a reversible motor 38 mounted on a platform 40 above the door. This motor has double pulley 42 on which cables 44, 46 are oppo- 3,504,729 Patented Apr. 7, 1970 sitely wound. Cables 44, 46 pass through eyebolts 49 suspended from ceiling 47 and terminate at eyebolts 48 near the bottom, rear edge of the door. An access door 53 can be provided in door section 20. To the extent described the double door installation is largely conventional.

Now according to the invention there are provided two latch assemblies 50 of identical construction at opposite lateral ends of the door. Each latch assembly 50 includes anelongated flat slide bar 52 shown to best advantage in FIG. 6. This bar has an elongated central longitudinal slot 54. The bar is movably supported by a vertical plate or panel 55 secured by bolts 59 to side wall 56 of the doorway. A guide shaft 60 is rigidly supported in a horizontal position by plate 55. This shaft extends through slot 54 and has flanges 61 at opposite sides of the bar 52 so that the bar can be guided by the shaft to slide along the shaft. The rear end 58 of slot 54 is turned upwardly so that the bar in open position of the latch extends forwardly and downwardly as shown in FIGS. 4 and 5 with shaft 60 engaged in the turned up end 58 of slot 54. A coil spring 62 is tensioned between a hole 64 at the forward end of the latch bar and a pin or bolt 66 on plate 55. The spring pulls the bar downwardly to a contact stop pin 68 carried by plate 55. The latch bar has an upwardly finger or hook 70 at its forward end. At the rear end of the bar is a hole 72 in which is engaged one end of a cable 74. The cable is entrained around a pulley 75 carried by plate 55. The cable extends upwardly to an overhead pulley 76 and then terminates on one section of a double pulley 78. Both cables 74 are wound in opposite directions on pulley 78. This double pulley is carried by shaft 79 of latch actuating motor 80 supported on platform 82 by panel 14.

On the lower door section 20 are catch means including two spaced eyebolts 84 extending rearwardly and provided with rollers 86 at their rear ends. Each eyebolt forms part of one latch assembly.

When the doors are fully closed the latch bar 52 of each assembly is tilted upwardly so that slot 54 is horizontal and hook 70 engages eyebolt 84 as best shown in FIG. 3. The bar is also pulled rearwardly so that shaft 60 is disengaged from turned up end 58 of slot 54. The cable 74 is tensioned and the door is pulled inwardly to assume a vertical position. The upper edge of the latch bar is in contact with another stop pin 88 carried by plate 55.

FIG. 4 shows the door 10 in lowered but unlocked position. The lower section 20 is inclined forwardly so that the upper edge of section 20 and lower edge of section 14 extend forwardly a few inches. FIG. 5 shows the door fully open, folded and elevated at which time both latch assemblies 50 are in open position.

FIG. 7 shows parts of an automatically operated circuit used to actuate motor 80. This circuit can be operated by remote radio control, local key switch, pushbutton switch or other control means. In any case a switch 102 will be connected to one terminal 104 of a power supply. This terminal will also be connected to contact 106 of relay 107 having a movable contact 108 normally closed with contact 106 when the relay is deenergized. Motor 80 is connected to movably contact 108 and to terminal 110 of the power supply. Thus the motor will be energized when switch 102 is open. When switch 102 is closed, relay coil 112 of the relay will be energized and contacts 106, 108 will open to deenergize the motor. The circuitry involving motor 38 which raises and lowers the doors is shown in greatly simplified form. Motor 38 is reversible. It is connected to reversing switch 115 to turn in one direction and raise the door. When the switch is reversed the motor reverses and lowers the door.

In operation of the door locking system, assume that the door 10 is closed as shown in FIGS. 1 and 3. The

motor 80 keeps cables 74 under tension and the door is held closed. Suppose switch 102 is now opened, the motor 80 will become deenergized as relay 107 becomes energized and the latch bar 52 of each latch assembly will be pulled forwardly and down by the spring 62. This will release eyebolts 84 and the door will swing forwardly to the partially open position shown in FIG. 4. Now the motor 38 can be operated to raise the doors to the elevated position shown in FIG. 5. After a time the motor 38 is reversed and the doors are lowered again to the partially open position shown in FIG. 4, and switch 102 is opened to deactivate relay 107. Contacts 106, 108, close and motor 80 is operated to draw up both cables 74 closing both latch assemblies 50 simultaneously. The retracted latch bars 52 pivot upwardly at the front. Hooks 70 engage forwardly of the rollers 86 and pull them rearwardly so that the door assumes the fully vertical position shown in FIG. 3. The latch assemblies remain in this active condition holding the door closed until they are actuated again to release it.

Many difierent types of circuits, timing schemes, and control means can be devised for operating the motors 38 and 80. In any case the two latch assemblies will cooperate to pull the partially open door into fully closed position and will hold it there. The system is arranged to be fail-safe, since a failure of the power supply will cause the latch assemblies to open as coil springs 62 pull the latch bars 52 down out of engagement with the eyebolts 84.

The system is relatively simple in structure, economical to manufacture, easy to install, foolproof and trouble free.

What is claimed is:

1. An automatic door closing system for a folding double door guided by vertical tracks at opposite lateral ends to move between a lowered vertical position and an overhead folded position, said door having sections pivoted on axially horizontal hinges, said system comprising a support mountable vertically behind the door at one end thereof, an elongated fiat latch bar having an upstanding hook at its forward end closest to the door; catch means carried by one section of the door and located near the hook for engagement thereby when the door is in lowered position, motor means mounted above the door; a first cable connected at one end to the other end of the latch bar and at its other end to said motor means; pulley means spaced from the other end of the latch bar, said cable being entrained on said pulley means; pivot means on said support, said latch bar having a longitudinally extending slot, said pivot means extending through said slot so that the latch bar is supported in a vertical plane, said latch bar pivoting in said vertical plane and sliding rearwardly in a direction away from the door on said pivot means when said motor means is energized to pull the cable taut and retract the cable via said pulley means; spring means connected between a point on said support below said latch bar and the forward end of the latch bar and tensioned to retract the latch bar from engagement with said catch means when the cable is slackened upon deenergization of said motor means; other motor means mounted above the door; and other cable means connected between said other motor means and the lowermost section of the door for raising and lowering the door, whereby when the door is fully lowered, said latch bar is pivoted by said first cable to engage the hook with the catch means against tension in said spring means, and then the latch bar is retracted rearwardly by the first cable to pull the door sections to fully vertical coplanar position and to keep the door sections in said vertical coplanar position while the first cable remains taut.

References Cited UNITED STATES PATENTS 836,810 11/1906 Kapus 292l09 917,969 4/ I909 Shinn 292-109 1,210,826 l/19l7 Minor 292109 1,412,871 4/ 1922 Johnson l-l89 2,607,586 8/1952 Schlytern l60l89 3,024,838 3/1962 Egleston et al l60l 93 3,224,493 12/1965 Houk l60189 PETER M. CAUN, Primary Examiner US. Cl. X.R. l60207 

